The present invention relates to a device for linearly moving a useful mass and by decoupling the momentum generated during the movement of the useful mass from the machine or machine foundation.
Devices of this type have been used since many years with machine tools. It is also known that dynamic processes used to accelerate useful masses along linear axes produce significant forces that have to be transferred to or absorbed by the machine bed or machine foundation. Dynamic movements along one axis can accidentally be transferred through the machine bed to another axis, which can result in processing inaccuracies, in particular workpieces that have low-quality surfaces. In addition, when a rotary motion is transformed into a translational motion—either by a transformation through a ball roller spindle or alternatively a rack/pinion assembly—the forces generated by the linear element can result in a loss in stiffness of the entire system. The transformation from a rotary motion into a translational motion is in general also associated with a significant loss in stiffness, which can be aggravated by the elasticity of the machine bed and/or the support of the drive train. This limits the dynamic characteristic of the machine, unless substantial changes are made in the machine design.
It would be desirable and advantageous to provide devices of this type so as to reduce and/or compensate disturbances caused by the motion transformation.
It would also be desirable and advantageous to provide an improved device for moving useful masses, which obviates prior art shortcomings and is able to specifically reduce the momentum transferred to the machine or machine foundation and compensate for disturbances caused by the transformation from rotary to translational motion.